BISC 1111 Lab Final

original quizlet by kschmeizer, NOT ME i just wanted to study for free tysm

Kilo

Kilo

1000; 10^3 ; k

Deci

0.1; 10^-1; d

Centi

0.01; 10^-2; c

Milli

0.001; 10^-3; m

Micro

0.000001; 10^-6; μ

Nano

0.000000001; 10^-9; n

Absorbance

a way to quantify the amount of a molecule in a solution is to measure this, or measure this of one of its colored products

Spectrophotometer

instrument that measures the proportion of light of a specific wavelength that is absorbed (or transmitted) by a molecule in solution

Standard Curve

depicts the relationship between known concentrations of the molecule and their corresponding absorbance

Beer-Lambert Law

The relationship between absorbance and the concentration of the pigment molecule follows this

Standard Curve of Absorbance v. Concentration

x-axis is concentration (μM), y-axis is absorbance (no units)

Absorbance Spectrum

a graph of a molecule's absorption versus wavelength of light; from it you can learn what wavelengths of light the molecule will absorb

Absorbance Equation

(ε)(l)(c); shows that absorbance is directly proportional to the concentration

ε

molar absorptivity constant

l

path length of light through the solution

c

concentration of molecule in the solution

Dilutions Equation

C1V1 = C2V2; C = concentration (M); V = volume (L)

Enzymes

a specific class of proteins that catalyze reactions through chemical or mechanical means; made of amino acids

Activation Energy

energy required to get a chemical reaction started; enzymes, like any other catalyst, lower the amount of this

Active Sites

three-dimensional configurations; most enzymes have one or more of these; this determines its catalytic ability

Substrate

the molecule(s) acted upon by the enzyme, attaches to the active site(s)

Cofactors

molecules like inorganic cations, such as Ca2+, Fe3+, Mg2+, or Mn2+, certain vitamin precursors, and/or other small inorganic molecules often aid in the binding process between a substrate and its enzyme; these are essentially molecules for the activation of certain enzymes

Coenzymes

organic molecules that play the same role as cofactors; have a different name due to its organic nature

Binding Complex

involves non-covalent forces such as ionic bonds, hydrogen bonds, or van der Waals forces, which are very short-lived

Enzyme Kinetics

the study of reaction rates of processes catalyzed by enzymes; usually measured as the amount of product ,made per unit of time for a given concentration of an enzyme

Factors that Affect the Reaction Rate of Enzymes

pH, temperature, and presence of inhibitors

Glucose Oxidase Assay

the objective is to measure the catalytic activity of the enzyme glucose oxidase to determine the rate at which it produces H2O2 and how much H2O2 it can produce

Saturated

every active site of every enzyme molecule is taken up by substrate molecules

Michaelis-Menten Kinetics

model of enzyme kinetics that takes the form of an equation describing the rate of enzymatic reactions, by relating reaction rate to the concentration of a substrate S.

Lineweaver-Burk Plot

plots the inverse of the substrate concentration on the x-axis and the inverse of the velocity on the y-axis; the y-axis is 1/Vmax and the x-intercept is (-1/KM)

Denatured

proteins with a compromised three-dimensional structure are considered to be this

Inhibitors

specific chemical molecules that impair a given enzymatic function

Competitive Inhibitor

competes with the substrate for binding to the active site but, once bound, cannot be transformed by the enzyme into product

Noncompetitive Inhibitor

binds at a site on the enzyme or enzyme-substrate complex other than at the active site; they tweak the structure of the enzyme, in particular, the active site, so that the enzyme can no longer bind its substrate or catalyze a reaction

Feedback Inhibition

the phenomenon where the output of a process is used as an input to control the behavior of the process itself, oftentimes limiting the production of more product

Michaelis-Menten Plot

v = VMax [S]/KM + [S]

v

velocity (reaction rate, on the y-axis of the graph)

VMax

maximum speed

[S]

substrate concentration (x-axis on the graph)

KM

the concentration of the substrate at which the reaction velocity is ½ of the maximum speed; specificity (or affinity) constant; tells us how well an enzyme binds to a substrate

A low KM

indicates that the enzyme does not need high concentrations of substrate to become saturated, which suggests that the enzyme is specific to that substrate

ELISA

Enzyme-Linked ImmunoSorbent Assay

Antigens

expressed on the surface of foreign substances; elicit a series of immune responses

Immune Response

production of antibodies by B-lymphocytes which bind to a specific region on the antigen

Epitope/Antigenic Determinant

specific region on the antigen that antibodies bind to

Antibody

produced by each B-cell; specific and binds to a very specific epitope on the antigen; specificity is so strong that they're able to discriminate among very similar epitopes

Polyclonal

the immune response to an antigen is always this, because the immune system expresses a wide variety of antibodies with structures diverse in both their binding regions as well as their effector regions

Binding Region

determines how and where an antibody binds to an antigenic epitope

Effector Regions

give the antibody options to deal differently with one and the same antigen

Polyclonal Antibodies

bind to multiple epitopes on the same antigen; produced by injecting a given antigen into a mammal, e.g. a rat, goat, rabbit; the mammal is bled periodically and the antibodies are removed from the blood serum, for its antibodies

Antiserum

blood serum that antibodies are removed from when the mammal is bled periodically

Monoclonal

the products of a single B-cell clone, and thus much more time-consuming

Myeloma Cells

cancerous C-cells which can divide forever

Hybridomas

the product of combining the short-lived B-cells with immortal myeloma cells; can live forever; either culture in vitro or injected into a second mammal

Ascites

antibody-rich fluid

Two basic variations on the ELISA test used for disease detection

1. Testing for the presence of an antibody against the disease antigen, or 2. Testing for the presence of the disease antigen itself

Horseradish Peroxidase

one enzyme commonly used for ELISA

What the basic ELISA test is used to test for

pregnancy, ovulation, human immunodeficiency virus (HIV), hepatitis B virus, and an array of other viral, bacterial, and fungal pathogens

False Positives

some occur because an individual may possess antibodies directed against human leukocyte antigens (HLA); another reason for this could be because the HIV antigen linked to the enzyme varies from one kit to another. Some use a recombinant HIV protein, while others use the HIV protein p24, which cross-reacts with antibodies formed against some fungi, such as those that cause candidiasis (yeast infection)

False Negatives

if the test is done prior to the rise in antibody levels in the infected individual, this may result

Polymerase Chain Reaction (PCR)

a technique used by scientists to amplify specific regions of DNA

Uses of PCR

by clinicians to amplify and identify viral or bacterial DNA, by forensic scientists to amplify small amounts of DNA found at crime scenes to create a genetic profile, by research scientists to amplify genes of interest for further study

How PCR Amplifies DNA

PCR amplifies (makes many copies of) one specific DNA Region without having to isolate the DNA from the billions of other DNA base pairs in the genome

DNA Template

the DNA containing the gene you wish to amplify

Primers

short strands of DNA complementary to the outer regions of the gene that serve as a starting point for DNA synthesis

DNA Polymerase

an enzyme that reads template DNA and joins dNTPs to create a new complementary strand of DNA

dNTPs

Deoxynucleotide triphosphates are the nucleotides that comprise DNA. They are adenosine (ATP), guanine (GTP), thymine (TTP), and cytosine (CTP), abbreviated as A, G, T, and C

Buffer

this is needed in the DNA reaction to maintain the optimal salt concentration and pH for the DNA polymerase to work most efficiently

Steps of PCR

denaturation, annealing, extension; steps are repeated 18-40 times to ensure that the template DNA is sufficiently amplified

Denaturation

the two DNA strands are separated from each other by heating the DNA to 94°C. This high temperature breaks the hydrogen bonds that hold the DNA strands together

Annealing

the reaction is cooled to about 53-68°C, allowing the primers to anneal, or form hydrogen bonds with, the template DNA. The primers are the starting point for the new, complementary strand of DNAthat will be created with each round of PCR

Extension

the DNA polymerase enzyme in the reaction is activated by heating the reaction to 72°C. The polymerase enzyme adds nucleotides to the growing complementary strand of DNA

Forward Primer

the primer that anneals to the beginning of the template DNA (the coding strand of DNA)

Reverse Primer

the primer that binds to the complementary strand

Direction of DNA

5' to 3'

Electrophoresis

thee movement of ions and other charged molecules, such as proteins and DNA, through a solution in response to an electrical field

Horizontal Gel Chamber

used to analyze DNA samples; a plexiglass box with two electrodes; one connected to the negative connector (black)of a DC power supply, while the other is connected to the positive connector (red); In between the electrodes is a gel and the entire gel and the ends of the electrodes are submerged in a buffer fluid

Voltage

measured in volts by a voltmeter; the supplied voltage creates an electrical field between these two electrodes in the electrophoresis chamber, so that the positive and negative ions move to the cathode and anode, respectively

Cathode

negatively charged region; DNA sample is put into a well, or depression, in the gel on the end with this

Anode

Since DNA carries a negative charge, the DNA molecules are pulled towards this end of the gel apparatus

Mendelian Genetics

the study of how genes are inherited from one generation to the next

Exceptions to Mendelian's Genetic Ratios

epistasis, incomplete dominance, sex-linkage, gene linkage

Classic F2 Mendelian ratios for two genes

9:3:3:1

Crossing-over

the crossover that is essentially a breakage of two adjacent chromosomes during prophase I of meiosis I, resulting in the exchange of genes between these two different chromosomes after meiosis I

Genetic Maps

a map of the relative locations of the genes on a given chromosome, i.e. a depiction of their relative positions to each other on a given chromosome

Parental Chromosome

indicates that the allele combination on a chromosome identical to the allele combination on one of the chromosomes that started meiosis

Recombinant Chromosomes

have alleles on them unlike the two chromosomes with Ab and aB combinations, due to crossovers

Unlinked Genes

if two genes are far apart on the same chromosome, or on different chromosomes, and all cells have a crossover between the two genes, then 50% of the products from meiosis would be recombinant chromosomes, and 50% would be parental chromosomes. These two genes are known as this

Linked Genes

Any two genes that show less than 50% recombinant chromosomes in the products of meiosis

Map Units of centiMorgans (cM)

the genetic distance between genes on a chromosome is measured in this; one of these equals the genetic distance that produces 1% recombinant chromosomes after meiosis

Gene Maps

shows the relative location of genes on chromosomes; established by analyzing the percentage of recombinant chromosomes produced by meiosis

Testcross

used in order to measure the percent of recombinant chromosomes or gametes; one has to mate the products of meiosis with the gametes (ab) produced by a homozygous recessive mate (aabb)

Chi Square Test

used to determine the probability of whether or not the stated hypothesis agrees with the observed data

Observed Value

the number of offspring counted with that coat color

Expected Value

what the hypothesis would predict for each class

Degrees of Freedom (df)

the number of independent classes minus one

Chi Square Value

X2 = (Observed - Expected)^2/Expected

ELISA is used to...

...detect the presence of antigens or antibodies against the antigen

In the ELISA lab, the purpose in the wash buffer is?

to wash the unbound sample out of the wells

Types of Immune Responses

Innate (non-specific) and Adaptive (specific)